1. Field of the Invention
The present invention relates to a vehicle having in-wheel motors and, particularly, to the arrangement of in-wheel motors and an internal combustion engine in a vehicle having an internal combustion engine for driving the vehicle.
2. Description of the Prior Art
As a vehicle having an internal combustion engine for driving front wheels or rear wheels, there has been known a vehicle having auxiliary driving motors in which the front wheels or the rear wheels are driven by an internal combustion engine and auxiliary driving electric motors are mounted to the rear wheels or front wheels to assist the driving force of the vehicle. FIG. 9(a) shows an example of a vehicle 60 having rear wheel auxiliary driving motors. In the vehicle 60 having rear wheel auxiliary driving motors, a generator 63 is mounted to an internal combustion engine 62 for driving the front wheels 60F and 60F, and auxiliary driving electric motors (in-wheel motors) 64 are mounted to the rear wheels 60R and 60R and are driven by power generated from the above generator 63 to drive the rear wheels 60R and 60R so as to assist the drive force of the above vehicle 60 (see Patent Document 1, for example).
FIG. 9(b) shows an example of an electric motor as the above electric motor, a motor 64 M having a speed reducer is often used. This motor 64M is a inner rotor type motor which comprises a stator 64S fixed to a motor case 64a on the outer side and a rotor 64R fixed to a motor shaft 64c through a support member 64b on the inner side. The above motor shaft 64c is rotatably supported by a bearing 64d installed in the motor case 64a and a bearing 64g installed in the carrier 64f of a planetary gear type speed reducer 64e, and the shaft 64h of the above carrier 64f which is the output shaft of the above speed reducer 64e is rotatably connected to the output shaft of a unshown clutch to transfer a torque.
As a direct drive type in-wheel motor having no speed reducer, there is proposed an outer rotor type in-wheel motor 73 as shown in FIG. 10 (see Patent Document 2, for example). In this in-wheel motor 73, a stator 73S is connected and supported to an upright 77 which is a fixing unit and arranged on the inner side of the wheel disk 72b of a direct drive wheel 72 and connected to a rotary shaft 74 connected to the above wheel disk 72b through a bearing 74J. Since a rotor 73R arranged on the outer side of the above stator 73S is supported to a first bracket 75a connected to the above rotary shaft 74 and a second bracket 75b connected to the above upright 77 through a bearing 77J in such a manner that it can turn, the rotor 73R is rotatably connected to the stator 73S. Therefore, as torque can be transmitted to the above wheel 72 by driving the above in-wheel motor 73, the above wheel 72 can be directly driven.
Motor control having excellent response which cannot be realized with a motor having a speed reducer like the above motor 64M can be realized by mounting a direct drive type in-wheel motor like the above motor 73.
Patent Document 1: JP-A 2003-32806
Patent Document 2: Japanese Patent No. 2676025